U.S. patent application number 14/351359 was filed with the patent office on 2014-09-18 for cushion for patient interface with localized region of reduced stiffness.
The applicant listed for this patent is KONINKLIJKE PHILIPS N.V.. Invention is credited to Justin Edward Rothermel.
Application Number | 20140261435 14/351359 |
Document ID | / |
Family ID | 47222163 |
Filed Date | 2014-09-18 |
United States Patent
Application |
20140261435 |
Kind Code |
A1 |
Rothermel; Justin Edward |
September 18, 2014 |
CUSHION FOR PATIENT INTERFACE WITH LOCALIZED REGION OF REDUCED
STIFFNESS
Abstract
An improved resilient cushion of a patient interface is
structured to engage the face of a patient and includes a
deformable bellows portion having a pair of deformable elements.
One of the deformable elements has an indentation formed therein
that provides a localized region of reduced stiffness and which
results in an improved fit on the face of the patient.
Inventors: |
Rothermel; Justin Edward;
(Monroeville, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KONINKLIJKE PHILIPS N.V. |
EINDHOVEN |
|
NL |
|
|
Family ID: |
47222163 |
Appl. No.: |
14/351359 |
Filed: |
October 24, 2012 |
PCT Filed: |
October 24, 2012 |
PCT NO: |
PCT/IB2012/055848 |
371 Date: |
April 11, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61551637 |
Oct 26, 2011 |
|
|
|
Current U.S.
Class: |
128/205.25 |
Current CPC
Class: |
A61M 16/0611 20140204;
A61M 16/0057 20130101; A61M 16/0683 20130101; A61M 16/0633
20140204; A61M 16/06 20130101; A61M 16/0622 20140204 |
Class at
Publication: |
128/205.25 |
International
Class: |
A61M 16/06 20060101
A61M016/06; A61M 16/00 20060101 A61M016/00 |
Claims
1. A resilient cushion that is structured to engage the face of a
patient and to form a seal between the face of the patient and a
supply apparatus that is structured to provide a flow of breathing
gas to an airway of the patient, the cushion comprising: a
deformable bellows portion comprising a first deformable element
and a second deformable element connected together at a vertex, the
bellows portion extending about the perimeter of a region which,
when the cushion is engaged with the face, is structured to be an
enclosed region situated between the face and the supply apparatus;
the first deformable element comprising a first leg that extends
from the vertex, the first deformable element being structured to
be engaged with the face of the patient; the second deformable
element comprising a second leg that extends from the vertex, the
second deformable element being structured to be engaged with the
supply apparatus; and at least one of the first leg and the second
leg having formed therein an indentation that extends along at
least a portion of the perimeter and that provides a localized
region of reduced stiffness that is localized along the perimeter
at a location that is structured to be situated generally in the
vicinity of the bridge of the nose.
2. The cushion of claim 1, wherein the indentation extends along at
least a portion of the perimeter that is structured to be situated
adjacent the nose of the patient.
3. The cushion of claim 2, wherein the indentation extends along a
portion of the perimeter that is structured to extend across the
bridge of the nose and adjacent the sides of nose.
4. The cushion of claim 1, wherein the first leg has a length
measured in a direction extending generally away from the vertex
and wherein the second leg has another length measured in a
direction extending generally away from the vertex, the length
being greater than the another length, the indentation being formed
in the second leg.
5. The cushion of claim 4, wherein the second deformable element
comprises an attachment element disposed on the second leg opposite
the vertex, the attachment element being structured to be connected
with the supply apparatus, the indentation being situated between
the vertex and the attachment element.
6. The cushion of claim 1, wherein the bellows portion comprises an
apex region that is structured to extend across the bridge of the
nose of the patient, and wherein the indentation has a width
measured in a direction extending generally away from the vertex
and a depth measured in a direction extending generally transverse
to the width, at least one of the width and the depth decreasing in
a direction extending along the perimeter generally away from the
apex region.
7. The cushion of claim 6, wherein the indentation extends between
a pair of terminations situated at alternate sides of the apex
region, and wherein the width and the depth both decrease in a
direction extending along the perimeter generally away from the
apex region and toward of the terminations.
8. A patient interface that comprises the cushion of claim 1 and
that is structured to be engaged with the face of a patient and to
provide a flow of breathing gas to an airway of the patient, the
patient interface further comprising: a supply apparatus that is
structured to be connected with a source of breathing gas and that
comprises at least a first support which comprises a post; and a
strap apparatus that is structured to extend around at least a
portion of the patient's head, the strap apparatus comprising a
strap and at least a first clip, the at least first clip being
mountable on an end of the strap, the at least first clip and the
end of the strap being alternatively connectable with the post to
enable the patient interface to be mounted on the patient.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This patent application claims the priority benefit under 35
U.S.C. .sctn.119(e) of U.S. Provisional Application No. 61/551,637
filed on Oct. 26, 2011, the contents of which are herein
incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention pertains to a patient interface for
delivering a flow of breathing gas to a patient and, in particular,
to an improved deformable cushion for a patient interface having
formed therein an indentation that provides a localized region of
reduced stiffness.
[0004] 2. Description of the Related Art
[0005] There are numerous situations where it is necessary or
desirable to deliver a flow of breathing gas non-invasively to the
airway of a patient, i.e., without intubating the patient or
surgically inserting a tracheal tube in their esophagus. For
example, it is known to ventilate a patient using a technique known
as non-invasive ventilation. It is also known to deliver continuous
positive airway pressure (CPAP) or variable airway pressure, which
varies with the patient's respiratory cycle, to treat a medical
disorder, such as sleep apnea syndrome, in particular, obstructive
sleep apnea (OSA), or congestive heart failure.
[0006] Non-invasive ventilation and pressure support therapies
involve the placement of a respiratory patient interface device
including a patient interface that is typically secured on the face
of a patient by a headgear assembly. The patient interface may be,
without limitation, a nasal mask that covers the patient's nose, a
nasal cushion having nasal prongs that are received within the
patient's nares, a nasal/oral mask that covers the nose and mouth,
or full face mask that covers the patient's face. It is known to
maintain such devices on the face of a wearer by a headgear having
one or more straps adapted to fit over/around the patient's head.
Because such respiratory patient interface devices are typically
worn for an extended period of time, it is important for the
headgear to maintain the patient interface in a desired position
while doing so in a manner that is comfortable to the patient.
[0007] It is also desirable, however, that the respiratory patient
interface device be relatively easy for the patient to install on
the head. Previous devices that have been comfortable for the
patient for extended periods and that maintain a reliable seal on
the patient's face for extended periods have typically been
relatively complicated devices that have been somewhat difficult to
install. It thus would be desirable to provide an improved patient
interface.
SUMMARY OF THE INVENTION
[0008] In certain embodiments, the general nature of the invention
can be stated as including resilient cushion that is structured to
engage the face of a patient and to form a seal between the face of
the patient and a supply apparatus that is structured to provide a
flow of breathing gas to an airway of the patient. The cushion can
be generally stated as including a deformable bellows portion
comprising a first deformable element and a second deformable
element connected together at a vertex. The bellows portion extends
about the perimeter of a region which, when the cushion is engaged
with the face, is structured to be an enclosed region situated
between the face and the supply apparatus. The first deformable
element can be generally stated as including a first leg that
extends from the vertex, with the first deformable element being
structured to be engaged with the face of the patient. The second
deformable element can be generally stated as including a second
leg that extends from the vertex, with the second deformable
element being structured to be engaged with the supply apparatus.
At least one of the first leg and the second leg has formed therein
an indentation that extends along at least a portion of the
perimeter and that provides a localized region of reduced
stiffness.
[0009] These and other objects, features, and characteristics of
the present invention, as well as the methods of operation and
functions of the related elements of structure and the combination
of parts and economies of manufacture, will become more apparent
upon consideration of the following description and the appended
claims with reference to the accompanying drawings, all of which
form a part of this specification, wherein like reference numerals
designate corresponding parts in the various figures. It is to be
expressly understood, however, that the drawings are for the
purpose of illustration and description only and are not intended
as a definition of the limits of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a front elevational view of an improved patient
interface in accordance with the present invention;
[0011] FIG. 2 is a side elevational view of the patient interface
of FIG. 1 installed on a patient;
[0012] FIG. 3 is an enlarged view of a portion of the patient
interface of FIGS. 1 and 2, partially disassembled;
[0013] FIG. 4 is a perspective view of a clip of the patient
interface of FIGS. 1 and 2;
[0014] FIG. 5 is a sectional view as taken along line 5-5 of FIG.
1;
[0015] FIG. 6 is a view similar to FIG. 1, except depicting a strap
of a strap apparatus connected with a pair of posts of the patient
interface;
[0016] FIG. 7A is a perspective view of an improved deformable
cushion in accordance with the present invention of the patient
interface of FIGS. 1 and 2;
[0017] FIG. 7B is another perspective view of the cushion of FIGS.
1 and 2;
[0018] FIG. 8 is a sectional view as taken along line 8-8 of FIG.
7B; and
[0019] FIG. 9 is an enlarged view of an indicated portion of FIG.
8.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENT
[0020] As used herein, the singular form of "a", "an", and "the"
include plural references unless the context clearly dictates
otherwise. As used herein, the statement that two or more parts or
components are "coupled" shall mean that the parts are joined or
operate together either directly or indirectly, i.e., through one
or more intermediate parts or components, so long as a link occurs.
As used herein, "directly coupled" means that two elements are
directly in contact with each other. As used herein, "fixedly
coupled" or "fixed" means that two components are coupled so as to
move as one while maintaining a constant orientation relative to
each other.
[0021] As used herein, the word "unitary" means a component is
created as a single piece or unit. That is, a component that
includes pieces that are created separately and then coupled
together as a unit is not a "unitary" component or body. As
employed herein, the statement that two or more parts or components
"engage" one another shall mean that the parts exert a force
against one another either directly or through one or more
intermediate parts or components.
[0022] Directional phrases used herein, such as, for example and
without limitation, top, bottom, left, right, upper, lower, front,
back, and derivatives thereof, relate to the orientation of the
elements shown in the drawings and are not limiting upon the claims
unless expressly recited therein.
[0023] An improved patient interface 2 in accordance with an
exemplary embodiment of the invention is depicted generally in
FIGS. 1 and 2. In FIG. 2, patient interface 2 is depicted as being
installed on the face of a patient 4. Patient interface 2 is
advantageously configured to provide a flow of breathing gas to the
airways of patient 4.
[0024] Patient interface 2 can be said to include a supply
apparatus 6 that is connected with a source of breathable gas, a
cushion 8, and a headgear 10. Cushion 8 is mounted to supply
apparatus 6 and is configured to deformably engage a face of
patient 4 and to form a seal between the face of patient 4 and
supply apparatus 6. Headgear 10 is connectable with supply
apparatus 6 and can be used to mount patient interface 2 on the
head of patient 4.
[0025] As can be understood from FIGS. 1 and 2, supply apparatus 6
can be said to include a frame 12 that includes a lower portion 14
and an upper portion 16. Frame 12 is a relatively rigid member
which may be formed out of an appropriate material, such as a
polycarbonate or other relatively rigid plastic material or other
materials. Supply apparatus 6 can further be said to include a
connector 18 mounted on frame 12. As can be understood from FIG. 1,
connector 18 is connected with a source of breathing gas 20 that
supplies a flow of breathing gas to patient interface 2. Connector
18 is in fluid communication with source of breathing gas 20 via a
hose that is not expressly depicted herein for purposes of
simplicity of disclosure. The breathing gas that is provided to
patient interface 2 can be any of a wide variety of gases including
combinations of gases such as air or other combinations of
gases.
[0026] Upper portion 16 of frame 12 includes a forehead brace 22
that is structured to engage the forehead of patient 4. The
engagement of forehead brace 22 with the forehead of patient 4
provides additional support to frame 12 and thereby assists cushion
8 in maintaining a seal with the face of patient 4 in order to
reliably provide the flow of breathing gas to the airways of
patient 4. It is noted, however, that other embodiments of the
patient interface can be configured to not include forehead brace
22 while still remaining within the scope of the present
concept.
[0027] Headgear 10 is depicted in FIGS. 1 and 2 as including an
upper strap 23 that is connected with forehead brace 22 and which
can be connected with the upper regions of the head of patient 4.
FIGS. 1 and 2 further depict headgear 10 as including a strap
apparatus 24 which, in FIGS. 1 and 2, is depicted as being
connected with lower portion 14 of frame 12 and which is depicted
in FIG. 2 as extending about the head of patient 4. As will be set
forth in greater detail below, strap apparatus 24 is connectable
with supply apparatus 6 and is detachable therefrom to facilitate
the installation of patient interface 2 on patient 4 and the
removal therefrom in a fashion that is simple and convenient for
patient 4.
[0028] More particularly, and as can be understood from FIG. 3,
supply apparatus 6 further comprises a pair of supports 26A and 26B
disposed at opposite sides of lower portion 14 of frame 12.
Supports 26A and 26B each include a post 28A and 28B that is
mounted to frame 12 with an upper brace 30A and 30B and a lower
brace 31A and 31B. Upper and lower braces 30A, 30B, 31A, and 31B
support posts 28A and 28B at positions spaced from frame 12 in such
a fashion to provide a passageway 32A and 32B adjacent each post
28A and 28B. More particularly, passageway 32A can be said to
extend generally between post 28A and frame 12 and between upper
brace 30A and lower brace 31A. Similarly, passageway 32B extends
between post 28B and frame 12 and additionally extends between
upper and lower braces 30B and 31B.
[0029] Posts 28A and 28B are configured such that an external
surface 33A and 33B is arcuate along at least a portion thereof. In
the exemplary embodiment depicted herein, the arcuate portions of
surfaces 33A and 33B are of a generally cylindrical shape which
permits strap apparatus 24 to be movably connected with posts 28A
and 28B, as will be explained in greater detail below. It is noted,
however, that in other embodiments not expressly depicted herein,
posts 28A and 28B potentially may have external surfaces that are
of another type of arcuate configuration, such as a spherical shape
and the like depending upon the needs of the particular
application.
[0030] As can be understood from FIGS. 1 and 2, strap apparatus 24
can be said to include a strap 34 and a pair of clips 36A and 36B.
Clips 36A and 36B are connectable with strap 34 at the opposite
ends thereof, as is depicted generally in FIG. 1. For example strap
36 could include hook and loop fasteners or other appropriate
structures at its ends to enable clips 36A and 36B to be mounted
thereon. An underside of clip 36A is depicted in greater detail in
FIG. 4.
[0031] More particularly, FIG. 4 depicts clip 36A as including a
housing 38 having a receptacle 40 formed therein that is structured
to removably receive post 28A. Receptacle 40 can be seen as
including an arcuate reception surface 42 situated opposite a lug
44 and between which post 28A can be received, as is depicted
generally in FIG. 5. Since reception surface 42 is shaped to have
an arcuate configuration that corresponds with that of the
cylindrical shape of surface 33A of post 28A, clip 36A is at least
somewhat pivotable with respect to post 28A when post 28A is
received in receptacle 40. Clip 36A further includes a strut 46
that extends between opposed portions of housing 38 and which is
structured to be connected with an end of strap 34, as is indicated
in FIG. 5.
[0032] User 4 can apply a compressive force to clips 36A and 36B to
press them onto posts 28A and 28B, respectively, with strap 34
extending around the rear of the head of patient 4. This causes
posts 28A and 28B to be received in receptacles 40 of clips 36A and
36B. In so doing, tactile and audible feedback are provided by
posts 28A and 28B being received against reception surfaces 42.
Such feedback facilitates installation since patient 4 can be
assured that patient interface 2 is properly assembled. Clips 36A
and 36B can be easily removed from posts 28A and 28B by patient 4
applying forces to pull clips 36A and 36B away from frame 12, which
dislodges posts 28A and 28B from receptacles 40 and enables removal
of patient interface 2 from patient 4.
[0033] Since clips 36A and 36B are mounted to the ends of strap 34
with, for instance, hook and loop fasteners or other structures on
strap 34, patient interface 2 can be mounted on patient 4 by
receiving clips 36A and 36B on posts 28A and 28B, respectively,
without a need of further adjustment of headgear 10. That is, once
patient interface 2 is properly mounted on patient 4 for the first
time, with strap 34 being adjusted on clips 36A and 36B to a state
of appropriate fit, clips 36A and 36B can be removed from and
reattached to supply apparatus 6 without a need of readjusting
headgear 10 after each installation. This promotes simple and
efficient installation and removal of patient interface 2, which is
advantageous. The audible and tactile feedback of clips 36A and 36B
when posts 28A and 28B are received in receptacles 40 further
promotes ease of installation since patient 4 can be assured that
patient interface 2 is properly installed.
[0034] Further advantageously, and as is indicated generally in
FIG. 6, strap 34 can alternatively be mounted directly to posts 28A
or 28B or both in the event that clips 36A or clip 36B or both
should become broken or lost. That is, FIG. 6 depicts posts 28A and
28B having the opposite ends of strap 34 mounted thereon by passing
the ends of strap 34 through passageways 32A and 32B and by
fastening the ends of strap 34 back on themselves with the
aforementioned hook and loop fasteners or other structures. Such
connection between an end of strap 34 and post 28A and another
connection of an opposite end of strap 34 with post 28B enables the
connections of strap 34 to be movable with respect to posts 28A and
28B, much in the fashion whereby clip 36A was movably mounted to
post 28A.
[0035] It thus can be seen that posts 28A and 28B are configured to
enable the ends of strap 34 to be mounted directly thereon in the
event that clips 36A or 36B or both should become unavailable. This
is advantageous since a potential typically exists that either or
both of clips 36A and 36B may be lost, broken, etc. If such
unavailability of clips 36A or 36B or both should occur at bedtime,
patient 4 can mount an end of strap 34 directly to posts 28A or 28B
or both in order that patient interface 2 can be mounted on patient
4 for the night to provide a flow of breathing gas to patient 4.
Patient 4 can thereafter order replacement components, as needed,
or potentially can continue to mount strap 34 directly to posts 28A
or 28B or both for an indefinite period of time depending upon the
needs of the particular situation. By providing supports 26A and
26B with the versatility to enable connection of strap apparatus 24
alternative thereto with clips 36A and 36B or with strap 34 itself
directly on posts 28A or 28B or both, patient interface 2 can be
made more reliable for patient 4. That is, patient interface 2 can
be made to be usable by patient 4 even in the event that certain
components thereof may become broken, lost, or otherwise
unavailable. Such versatility improves the usability of patient
interface 2 and increases the likelihood of therapeutic treatment
that is provided to patient 4.
[0036] Cushion 8 is further depicted in FIGS. 7A-9. In accordance
with the present invention, cushion 8 is advantageously configured
to provide an enhanced fit on patient 4 to more reliably form a
seal between the face of patient 4 and supply apparatus 6. Cushion
8 is formed of a resilient, deformable material such as a silicone,
rubber, or other material, by way of example. The seal formed
between cushion 8 and the face of patient 4 resists leakage of the
flow of breathing gas between cushion 8 and the face of patient 4,
which promotes the flow of breathing gas being supplied to the
airways of patient 4 rather than leaking from patient interface
2.
[0037] Cushion 8 can be said to include a bellows portion 48 that
is deformable and that is collapsible in the fashion of a
convolution of a convoluted deformable structure. Bellows portion
48 can be said to include a first deformable portion 50 that is
engageable with the face of patient 4 to form a seal therewith.
Bellows portion 48 can be said to further include a second
deformable portion 52 that is connectable with supply apparatus 6.
In the exemplary embodiment depicted herein, cushion 8 is molded to
frame 12 to connect a peripheral region of frame 12 with second
deformable portion 52. More particularly, and as can be understood
from FIGS. 7A-8, second deformable portion 52 can be said to
further include an attachment element 64 that is connected with
frame 12 via, for example, the aforementioned molding operation,
although such attachment is not expressly depicted in FIGS. 7A-9
for purposes of simplicity of disclosure. Other formation
methodologies can be employed without departing from the present
concept.
[0038] First and second deformable portions 50 and 52 are joined
with one another at a vertex 54 that is indicated generally in
FIGS. 8 and 9. More particularly, first deformable portion 50
includes a first leg 56 and a patient engagement element 58 that
are connected together. As can be seen in FIG. 9, first leg 56 can
be said to extend in a direction generally away from vertex 54 and
to have a length 60 measured in a direction generally away from
vertex 54. Second deformable portion 52 includes a second leg 62
that can likewise be said to extend away from vertex 54 and to have
a length 66 measured in a direction generally away from vertex 54.
Length 60 of first leg 56 is greater than length 66 of second leg
62, whereby second leg 62 can be said to have a greater stiffness,
i.e., spring constant, than that of first leg 56.
[0039] As can be understood from FIG. 7A, cushion 8 can be said to
enclose a region 68 which, when patient interface 2 is installed on
patient 4, is enclosed within cushion 8 and is disposed between
supply apparatus 6 and the face of patient 4. More particularly,
cushion 8 can be said to extend about a perimeter of region 68.
[0040] In accordance with the present invention, second leg 62 has
formed therein an indentation 70 that provides a region of reduced
stiffness which can be said to be localized in the region of the
indentation 70. That is, it can be seen from FIG. 9 that first leg
56 and second leg 62 each have nominal thicknesses (i.e., in a
direction transverse to lengths 60 and 66 and into to plane of the
page of FIG. 9) that are roughly similar. As such, the relatively
shorter length 66 of second leg 62 compared with the relatively
longer 60 of first leg 56 indicates that second leg 62 would
generally be stiffer in bending with respect to vertex 54 than
first leg 56. However, since second leg 62 has indentation 70
formed therein, indentation 70 reduces the thickness of second leg
62 at a location generally between vertex 54 and attachment element
64 to provide a region of reduced stiffness at the location of
indentation 70. Second leg 62 thus has enhanced localized
deformability in the vicinity of indentation 70, and such enhanced
deformability improves the fit of cushion 8 on the face of patient
4.
[0041] Cushion 8 can be said to include an apex region 74 that is
shown in FIGS. 7A and 7B. Apex region 72 can be said to extend
generally across the bridge of the nose patient 4 when patient
interface is installed on patient 4 in a fashion demonstrated
generally in FIG. 2. As can be understood from FIG. 7B, indentation
70 extends between a pair of terminations of 72A and 72B disposed
on opposite sides of cushion 8. Since apex region 72 is situated
generally across the bridge of the nose of patient 4 when patient
interface 2 is installed on patient 4, it can be understood that
the portions of indentation 70 that extend between apex region 74
and terminations 72A and 72B are situated adjacent the sides of the
nose of patient 4 when patient interface 2 is installed on patient
4.
[0042] As can be best understood from FIG. 9, indentation 70 is of
a width 76 that is measured in a direction generally away from
vertex 54, i.e., parallel to the direction of length 66 of second
leg 62. Indentation 70 can also be said to have a depth 78 in a
direction transverse to width 76. FIG. 7B depicts indentation 70 as
having its width 76 and depth 78 at their maximum dimensions in the
vicinity of apex region 74. Moreover, and as can be understood from
FIGS. 7A-8, at least one of width 76 and depth 78 gradually
decreases as indentation 70 extends in a direction from apex region
74 generally toward terminations 72A and 72B. In the exemplary
embodiment depicted herein, both width 76 and depth 78 decrease
along the length of indentation 70 in a direction generally away
from apex region 74 toward the terminations 72A and 72B.
[0043] It thus can be understood that by providing indentation 70
in the vicinity of the bridge of the nose of patient 4 and the
sides of the nose of patient 4, an enhanced fit between cushion 8
and the nose of patient 4 is provided. Such enhanced fit is
provided by the localized region of reduced stiffness, i.e., region
of increased compliance, in the vicinity of indentation 70. That
is, when cushion 8 is received on the face of patient 4, first and
second deformable portions 50 and 52 themselves may deform, plus
second leg 62 further deforms at the region of enhanced compliance
afforded by indentation 70. This provides an ability to accommodate
a greater variety of nose geometries than was previously possible.
Such improved fit increases the comfort to patient 4 and improves
the reliability of the seal that is formed between cushion 8 and
patient 4, which is desirable.
[0044] It is noted that in other embodiments of cushion 8,
indentation 70 can be of other configurations, such as having
different dimensions or being positioned in a different location.
Moreover, it is understood that more than one indentation can be
formed on cushion 8, and such indentations can be formed on either
or both of first and second legs 56 and 62 depending upon the needs
of the particular application. It thus can be seen that any desired
type of localized region of reduced stiffness can be provided on
cushion 8 depending upon the needs of the particular application.
It thus can be understood that indentation 70 is merely one example
of a single instance of a localized region of reduced stiffness,
i.e., increased compliance, and that cushion 8 can be configured in
other embodiments to include any number of such regions of reduced
stiffness in any of a variety of locations thereon depending upon
the needs of the particular application.
[0045] In the claims, any reference signs placed between
parentheses shall not be construed as limiting the claim. The word
"comprising" or "including" does not exclude the presence of
elements or steps other than those listed in a claim. In a device
claim enumerating several means, several of these means may be
embodied by one and the same item of hardware. The word "a" or "an"
preceding an element does not exclude the presence of a plurality
of such elements. In any device claim enumerating several means,
several of these means may be embodied by one and the same item of
hardware. The mere fact that certain elements are recited in
mutually different dependent claims does not indicate that these
elements cannot be used in combination.
[0046] Although the invention has been described in detail for the
purpose of illustration based on what is currently considered to be
the most practical and preferred embodiments, it is to be
understood that such detail is solely for that purpose and that the
invention is not limited to the disclosed embodiments, but, on the
contrary, is intended to cover modifications and equivalent
arrangements that are within the spirit and scope of the appended
claims. For example, it is to be understood that the present
invention contemplates that, to the extent possible, one or more
features of any embodiment can be combined with one or more
features of any other embodiment.
* * * * *